It is well known that reserve proteins are present in the subterranean storage tissue of sweet potatoes, white potatoes and the like. By contrast, the presence of reserve proteins has not yet been found in the subterranean tissue of root vegetables which are crops having edible roots, such as carrots.
Carrot roots have been used as a root vegetable for food; it has, however, been found that they contain only small amounts of proteins essential to the maintenance of health. Thus, it has been desired that high-protein carrots are developed by higher expression of proteins which are present in small amounts but specifically in the carrot roots. For this purpose, it has been necessary to find, first of all, proteins which can be specifically expressed in carrot roots and genes coding for these proteins.